This invention relates generally to joint simulators for testing purposes, and more specifically to joint simulators for testing components of a joint in articulation relative to one another under a load.
Artificial or prosthetic devices for replacing defective joints in humans have been the subject of extensive research and development efforts for many years, especially with regard to hip and knee joints, and more recently with spinal joints. In the design of such devices, it is advisable to subject the components of each new design to static and dynamic testing. Such testing is necessary to ensure that a particular design does not fail prematurely. Thus, a need exists within the medical equipment industry to assess the endurance properties of components of joint replacements.
While machines suitable for testing artificial or prosthetic hip and knee joints are known and are available to provide a variety of loading and articulation combinations, such machines have a variety of shortcomings, including large size, significant cost (both of purchase and maintenance), and slow speed. Moreover, many joint testing devices have been developed specifically for use with hip and knee joints, and in that respect are unsuitable for use with the growing number of spinal implants. The need to retrofit or completely redesign such machines for use with spinal implants increases the cost, and in some cases, the size.
Some devices have addressed these shortcomings to some degree. Enduratec (Minnetonka, Minn.) manufactures a Spinal Disc Implant Wear Testing System as well as a Spinal Disc Implant Wear Testing System, the respective capabilities and features of which are summarized at http://www.enduratec.com/testapp.cfm/tid/29 and http://www.enduratec.com/testapp.cfm/tid/27, respectively. While utilizing newer technologies to increase speed and minimize size, these device are nevertheless costly and complicated in function for many uses.
Therefore, it is an object of the invention to provide a joint simulator testing machine that efficiently effects articulation of joint components under a load. It is also an object of the invention to provide a joint simulator testing machine that provides easy adjustment of the articulation pattern. Other objects of the invention not explicitly stated will be set forth and will be more clearly understood in conjunction with the descriptions of the preferred embodiments disclosed hereafter.